# print('%2d-%02d' % (3, 1))
print('%02d%.2f' % (1, 3.14159))
print('age: %s . Gender : %s' % (25, True))
s1 = 72
s2 = 85
r = (s2 - s1) / s1 * 100
print('小明提高了:%.1f%%' % r)
print('{0}成绩提高了{1:.1f}%'.format('小明', r))

classmates = ['1', '2', '3']
print(classmates)
classmates.append('4')
print(classmates)
classmates.insert(0, '5')
print(classmates)
classmates.pop(0)
print(classmates)
